SIDPLAY is a Commodore 64 music player. It emulates the sound chip and other internals of the Commodore 64 home computer to play back music that was originally written on it. The sound chip of the C64 is called the "Sound Interface Device" or SID, and therefore this music is known as SID music. The SID chip is basically a three voice synthesizer on a chip. The unusual combination of digital and analogue circuitry is the reason for its distinctive sound.